Question: Express your answer as a mixed number simplified to lowest terms. $7\dfrac{8}{9}-2\dfrac{3}{9} = {?}$
Separate the whole numbers from the fractional parts: $= {7} + {\dfrac{8}{9}} - {2} - {\dfrac{3}{9}}$ Bring the whole numbers together and the fractions together: $= {7} - {2} + {\dfrac{8}{9}} - {\dfrac{3}{9}}$ Subtract the whole numbers: $=5 + {\dfrac{8}{9}} - {\dfrac{3}{9}}$ Subtract the fractions: $= 5+\dfrac{5}{9}$ Combine the whole and fractional parts into a mixed number: $= 5\dfrac{5}{9}$